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A researcher is investigating the relationship between the existing species diversity in a community and the ability of an introduced nonnative species to destabilize the community. Which of the following graphs is most consistent with the claim that communities with high diversity are more resistant to change than are communities with low diversity?

The first law of thermodynamics states that “energy cannot be created or destroyed, it can only be transferred or transformed.” What does this mean for biological systems?

There is a horizontal rectangle that is labeled D N A. The rectangle is divided into 9 boxes. From left to right, the first box is labeled P sub r, the second box is labeled trp R, the third box is labeled promoter, the fourth box is labeled Operator, the fifth box is labeled trp E, the sixth box is labeled trp D, the seventh box is labeled trp C, the eighth box is labeled trp B, and the ninth box is labeled trp A. Above the rectangle on the left is a large oval shape labeled R N A Polymerase. An arrow extends from the oval shape to the right and points to an X that is positioned above the boxes labeled Promoter and Operator. An irregular shape that looks like half of a circle and which is labeled R is positioned on top of the boxes labeled Promoter and Operator. A smaller oval shape labeled T is positioned partly on top of the shape labeled R. Underneath the rectangle, an arrow points downward from the box labeled trp R to a small, horizontal rectangle labeled trp R m R N A. On the left side of the rectangle is a 5 prime and a dash. On the right side of the rectangle is a dash and a 3 prime. An arrow points from the rectangle to a large oval shape labeled R. The large oval shape has a smaller oval shape cut out of it. To the left of the large oval shape are the words Inactive Repressor. A horizontal arrow points from the large oval shape to an irregular shape that looks like half of a circle and which is labeled R. A smaller oval shape labeled T is positioned partly on top of the shape labeled R. To the left of the irregular shape are the words Active Repressor. Above and to the left of the irregular shape is a small oval shape labeled T. A curved arrow extends from the shape labeled T down and to the right, eventually merging with the horizontal arrow that extends from the large oval shape on the left to the irregular shape on the right. A curved arrow extends from the irregular shape up and counterclockwise to point to the same shape that is positioned on top of the boxes labeled Promoter and Operator. There is a key below the figure that reads R equals Repressor molecule, T equals Tryptophan molecule, P sub R equals Promoter for the trp R gene, trp R equals Repressor gene, and Operator equals Binding site for repressor molecule. The Trp operon is a coordinately regulated group of genes (trpA–trpE) that are required for tryptophan biosynthesis in E. coli. Based on the figure above, which of the following correctly describes the regulation of the Trp operon?

Table 1. Types and properties of nitrogenous wastes produced by several vertebrates. Representative Vertebrate Primary Nitrogenous Waste Product Ammonia Urea Uric Acid Fish X Tadpole X Frog X Reptile X Bird X Mammal X Property of Nitrogenous Waste Product Solubility in Water High High Low Toxicity High Medium Low The table above shows the types and properties of nitrogen-containing wastes produced by several vertebrates. Which of the following is the best evolutionary explanation of the data?

There is strong evidence that two species of cliff-dwelling birds have nested in the same environment and fed in the same water for thousands of years, with each having stable population sizes. Based on this information, which of the following statements is the best conclusion?

The brown anole (Anolis sagrei) is a species of lizard native to Cuba that has been introduced into the southeastern United States. The range of brown anoles in the United States has been expanding, and they are now competing with native green anoles (Anolis carolinensis). Some of the characteristics of the green and brown anoles are shown in Table 1. Table 1. Characteristics of two anole speices Anole Species Body Length Limb Length Relative to Body Length Toe Pad Size Relative to Body Length Cold Tolerance A. sagrei (brown anole) 55-80 mm Long Intermediate 30-35 °C A. carolinensis (green anole) 45-85 mm Short Very large 25-30 °C A cladogram showing the relationships between some anole species is shown in Figure 1. The base of the cladogram is divided into two branches at the first node. The species indicated at the end of the top branch is A. carolinensis. The bottom branch divides further into two branches at the second node of the cladogram. The upper of the two branches divides into two more branches, and each of these two branches further divides into two branches. The four species indicated at the ends of the branches are, from top to bottom, A. stratulus, A. evermanni, A. cristatellus, and A. gundlachi. The lower of the two branches from the second node also further divides into two branches. The species indicated at the end of the top branch is A. sagrei. The bottom branch divides into two more branches. The species indicated at the ends of the two branches are A. valencienni and A lineatopus. Figure 1. Cladogram of some anole species Which of the following is the outgroup in the cladogram shown in Figure 1?

Researchers were modeling the effects of repeated cycles of isolation with occasional interbreeding among five hypothetical fish species (species A, B, C, D, and E) found in two separate lakes (lakes I and II) that are occasionally joined by flooding, as shown in Figure 1. The research team indicated that species A would be considered to be the single common ancestor of species B, C, D, and E. There are two lakes and Lake Roman numeral 1 is to the left of Lake Roman numeral 2. Lake Roman numeral 1 is very small, and contains fish populations A and B. Lake Roman numeral 2 is extremely large and there are three small islands located in Lake Roman numeral 2 on the left side of the lake. The fish populations A, D, and C are along the right side of the lake in that order, and E is on the left side of the lake below the largest island. Figure 1. Current locations of populations of fish species A, B, C, D, and E Which of the following data could best support the claim that species B arose from a speciation event in Lake I?

A group of students designed an experiment to determine the effect of compost on the germination and growth of plants. The students set up experimental plots by mixing different ratios of soil and compost. They planted 20 pea and 20 melon seeds in each plot and watered each plot regularly. The students recorded the number of seeds that germinated, and as the plants grew, they recorded plant length, number and size of leaves, and general health observations. The following observations were recorded. In all treatments, more pea seeds germinated than melon seeds. There was a week of rainy weather at three weeks. Melon plants developed a fungal growth at four weeks. Melon plants grew longer than pea plants, but many melon leaves showed signs of yellowing as the weeks passed. The students concluded that pea plants grew better in compost than did melon plants. Which of the following best addresses the validity of the conclusion made by the students?

In the American Southwest, annually emerging cicadas are dependent upon the cottonwood trees in the floodplain. Adult male cicadas perch in the cottonwood trees and chirp to attract females. Females lay their eggs in the branches of the cottonwoods, and, upon hatching, the cicada nymphs drop to the ground, burrow into the soil, feed on the tree roots, and later emerge as adults. Other organisms in the floodplain community prey on the cicadas, as shown in the food web. Arrows extend from the cicada to a yellow billed cuckoo, a sparrow, a lizard, a wasp, a black widow, and a kestrel. An arrow extends from a cottonwood to the cicada. An arrow extends from a lizard to a kestrel. An arrow extends from a sparrow to a kestrel. An arrow extends from a yellow billed cuckoo to a kestrel. Figure 1. Food web in floodplain community Human activity has caused a decrease in the amount of flooding and an increase in the incidence of wildfires in the floodplain. In an investigation into the recent changes in the floodplain ecosystem, researchers monitored the soil temperature, amount of cottonwood ground coverage (i.e., area of the ground that is shaded by leaves), and cicada emergence for a period from mid-June until late July. The results of the investigation are represented in Figure 2 and Figure 3. The horizontal axis is labeled “Cottonwood Ground Coverage, in percent,” and the numbers O through 100, in increments of 20, are indicated. The vertical axis is labelled “Mean June Soil Temperature, in degrees Celsius,” and the numbers 18 through 28, in increments of 2, are indicated. The line of best fit is shown. The line begins at the point with coordinates 2 percent of cottonwood ground coverage comma 25 degrees Celsius and moves directly downward and to the right ending at the point with coordinates go percent cottonwood ground coverage and 19 degrees Celsius. Figure 2. Effect of cottonwood ground coverage on soil temperature The horizontal axis is labeled “Mean June Soil Temperature, in degrees Celsius,’ and the numbers 18 through 28, in increments of 2, are indicated. The vertical axis is labeled “Mean Emergence Date,’ and the dates 6 13 through 7 23, in increments of 5 days, are indicated. The line of best fit is shown. The line begins at the point with coordinates 19 degrees Celsius comma the date 7 21 and moves directly downward and to the right ending at the point with coordinates 26 point 5 degrees Celsius comma the date 6 13. Figure 3. Relationship between soil temperature and cicada emergence date To assess the impact of wildfires on soil temperature and cicada emergence, the researchers compared mean emergence dates for two natural sites where portions had been affected by wildfire. In addition, cicada emergence was monitored at an experimental site where the soil temperature was experimentally maintained. The data are shown in the table. MEAN CICADA EMERGENCE DATES AT SITES AFFECTED BY WILDFIRES OR WITH EXPERIMENTALLY CONTROLLED SOIL TEMPERATURE The table shows Mean cicada emergency dates for Natural Site 1, Natural Site 2, and Experimental Site. For Natural Site 1, the Mean Emergency Date for Unburned is July 8, and for Burned is June 18. For Natural Site 2, the Mean Emergency Date for Unburned is July 15, and for Burned is July 3. For Experimental Site, the Mean Emergency Date for 24 degree Celsius is July 14, and for 27 degree Celsius is July 5. Based on the data, which of the following describes the most likely relationship between wildfires, soil temperature, and the timing of cicada emergence in the same year?

Humans are fairly unique among species in that we exhibit reciprocal altruism. This is thought to have evolved because we live in large, stable social groups. Which of the following is an example of reciprocal altruism?